The subject matter disclosed herein generally relates to elevator systems and, more particularly, to sensing elevator car guiding devices for elevator systems to connect an elevator car to a guide rail.
An elevator system typically includes a plurality of belts or ropes (load bearing members) that move an elevator car vertically within a hoistway or elevator shaft between a plurality of elevator landings. When the elevator car is stopped at a respective one of the elevator landings, changes in magnitude of a load within the car can cause changes in vertical motion state (e.g., position, velocity, acceleration) of the car relative to the landing. The elevator car can move vertically down relative to the elevator landing, for example, when one or more passengers and/or cargo move from the landing into the elevator car. In another example, the elevator car can move vertically up relative to the elevator landing when one or more passengers and/or cargo move from the elevator car onto the landing. Such changes in the vertical position of the elevator car can be caused by soft hitch springs and/or stretching and/or contracting of the load bearing members, particularly where the elevator system has a relatively large travel height and/or a relatively small number of load bearing members. Under certain conditions, the stretching and/or contracting of the load bearing members and/or hitch springs can create disruptive oscillations in the vertical position of the elevator car, e.g., an up and down “bounce” motion.